Passengers take part in the No Pants Subway Ride in Prague, Czech Republic, Sunday, Jan. 8, 2017. The No Pants Subway Ride began in 2002 in New York as a stunt and has taken place in cities around the world since then. (AP Photo/Petr David Josek)

NEW YORK (AP) — Subway riders in New York City and other places around the world should be ready for an eyeful when their fellow transit users strip down to their underwear.

The annual No Pants Subway Ride is taking place Sunday.

The event is organized by the Improv Everywhere comedy collective. It started in 2002 in New York with seven participants.

Organizers say pants-less subway rides are scheduled to take place this year in dozens of cities around the world. Philadelphia’s version is sponsored by a laundry delivery service.

Participants are told to get on trains and act as they normally would and are given an assigned point to take off their pants. They’re asked to keep a straight face and respond matter-of-factly to anyone who asks them if they’re cold.